A Multi-Dissolved Oxygen Array Chip Integrated with Concentric Stair-Like Microstructures for Rapid Estimation of Embryo Respiratory Activity

2023 Taiwan Society for Reproductive Medicine Annual Conference Prize Paper Presentation (Basic Science)

Ping-Feng Yang^*1, Chia-En Lee¹, En-Hui Cheng², Yi-Ping Lin², Han-Ni Tsai², TsungHsien Lee^3,4, Chun-I Lee^2,3,4, Maw-Sheng Lee^2,3,4, Ching-Chou Wu^1*

Department of Bio-Industrial Mechatronics Engineering, National Chung Hsing University.[1] Division of Infertility Clinic, Lee Women’s Hospital.[2] Institute of Medicine, Chung Shan Medical University.[3] Department of Obstetrics and Gynecology, Chung Shan Medical University Hospital.[4]
 

Study Question

Currently, the clinical pregnancy ratio of single embryo implantation is only approximately 50-60%, indicating that not every embryo can successfully grow. Although the morphological assessment of embryos can select healthy embryos to improve the pregnancy ratio, it only reaches about 70% after analysis with expensive instruments and long-term AI training. Currently, there is a lack of medical devices in clinical practice to monitor embryonic energy metabolism. Therefore, integrating non-invasive respiratory activity estimation techniques to select the optimal embryos for implantation is crucial for infertility patients.
 

Study Design, Size, Duration

The study aims to establish a label-free electrochemical embryonic respiration sensing chip for grading embryo status for clinic implantation criteria. The chip can quantify the oxygen consumption rate (OCR) of embryos with dissolved oxygen (DO) ultramicroelectrode array after using diffusion model analysis. The concentric stair-like microstructures are feasible for positioning a single embryo in the center position of the DO array. The thin-film Pt electrode can supply a stable reference potential for DO measurement. Before a clinical trial, age-different or H2O2-treated mouse embryos are used as models to compare the OCR value of different embryos.
 

Materials, Setting, Methods

The chip has been fabricated by microfabrication techniques from the Bio-Medical Micro-Analysis-System Lab, Department of BioIndustrial Mechatronics Engineering, National Chung Hsing University. The age different or H2O2-treated mouse embryos are used as models to compare the OCR value of different embryos from the Division of Infertility Clinic, Lee Women’s Hospital.
 

Main Results

The expected results are that young mouse embryos have a higher OCR value than older or H2O2-pretreated mouse embryos.
 

Conclusion

The chip has been successfully fabricated by microfabrication techniques. The single mouse embryo can be captured in the center of concentric stair-like microstructures. The DO concentration can be normalized in standard buffer and zero-oxygen Na2SO3 solution. Furthermore, the device has passed the biocompatibility testing certification after gamma-ray sterilization. In the preliminary result, this device can successfully quantify the embryo OCR of young mouse embryos. This device shows promising potential to grade the embryo status for improving implantation ratio in clinical uses.